motronic help needed

[amalventano@sc.rr.com (Allyn)]

update:
- from pete (thescirocco), this may actually be digifant 2.
- cleaned out the ISV, did get some gunk out of it, but it wasnt enough to stop
it from working normally (verified by problem still existing).
- did some more watching/listening/etc, and realized that its as if the engine
starts to idle rough anywhere below 1050 rpm. i'm sure the engine management
wants it to idle lower, but keeps bumping it back up to repeatedly achieve a
smooth idle, only to start over and head back to that hard-coded idle speed.
- i cranked down on the throttle body idle speed screw until i went beyond the
range of control of the isv and dropped the idle to 900. it idles a little
stuttery at that speed, but still holds a decent idle. i would leave it like
this, but that prevents the engine management from controling the idle, which i
would rather not do.
- the cam+exhaust may be causing the stumbly idle, or it may be something else.
i'm open to suggestions.
- final note: this problem existed since i got the car. it has remained constant
as far as how bad it is.

so... should i put a chip in this thing?
thx in advance for help
Al


----- Original Message -----
From: <brianm@earendel.org>
To: "Allyn" <amalventano@sc.rr.com>
Cc: "scirocco list" <scirocco-l@scirocco.org>
Sent: Monday, December 02, 2002 11:44 PM
Subject: Re: motronic help needed


>
> Idle stab valve...
> look up the audifans page for cleaning technique... basically clean the
> shot outta it w/ carb cleaner..
>
> On Mon, 2 Dec 2002, Allyn wrote:
>
> > car: 87 jetta wolfsburg 2 dr, 280 k miles
> > mods: unknown cam, tt exhaust
> > problem: idle fluctuates from 1000 to 1300 rpm at 5 second period. smooth
> > fluctuation, with no sudden changes in rpm.
> > it seems as though if it went below 1000 it would start stumbling, and the
> > engine mgmt brings it back up to prevent a stall. it never gets a chance to
go
> > that low, as it goes back up to 1300.
> >
> > suggestions?
> >
> > thx in advance
> > Al
> >
> >
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> >
>
>